Reinforced fibreboard box construction



Aug. 17, 1965 GLASSCO ETAL 3 0 REINFORCED FIBREBOARD BOX CONSTRUCTION Filed July 16, 1962 2 Sheets-Sheet 1 F r l 23 I30 24 3/ 25 a2 26 so 24 ag w 2? as 27 DONALD EG. GLASSCO JOHN M. BRATTON INVENTORS.

WWW

ATTOPNE VS Aug. 17, 1965 D. E. a. GLASSCO ETAL 3,201,022

REINFORCED FIBREBOARD BOX CONSTRUCTION 2 Sheets-Sheet 2 Filed July 15. 1962 DONALD E.G. GLASSCO JOHN M. BRATTON INVENTORS.

ATTORNEYS United States Patent M REHNFGRQED FIBREBGARD 30X CONSTRUfiTEQN Donald E. G. Giassco, Tempie City, and John M. Bratton,

Los Aiarnitos, Calif, assignors to Put-ex Qorporation,

Ltd, South Gate, tlalifi, a corporation of Qaiifornia Filed .liuly 16, 1962, Ser. No. 299,932 9 Ciaizns. (Cl. 22il15) This invention relates generally to the fabrication and construction of compartmented boxes. More particularly the invention has to do with the provision of novel boxboard or pasteboard boxes used for warehousing and shipping plastic containers, characterized as having substantially increased strength including crush resistance, and as affording substantial economies or savings in fabrication and material cost.

Among the objects of the present invention are to provide glued-in box dividers having the advantages of imparting increased strength, internal support and rigidity to the box. These objects are realized in accordance with the invention through the provision of a serpentine series of boxboard reinforcing panels extending within the box interior with corner hinging and with attachment to the box side panels, so that series alternate reinforcing panels extend crosswise of the box interior and remain parallel to the box end panels in positions of progessive parallelograrns collapse. The glued-in dividers are found to hold the box side panels essentially flat and straight even when the box fails, and because the side panels are tied together the dividers tend to cancel out normal outward bulge of the side panels. Also, the divider panels extending crosswise of the box interior remain under tension and under rigid support at each hinged end thereof when the boxes are compression loaded as by stacking, so that the dividers tend to remain fiat and vertically straight. The side walls of the box also coact with the reinforcing panels bonded thereto to provide increased stiffness and to prevent independent or premature collapse.

It is another feature of the invention that the reinforcing panels extending crosswise of the box interior have edges positioned to transmit closed box flap loading, thereby lending substantially greater internal support, particularly at the box center region which tends to cave under the pressure of boxes placed crosswise in the layer above. In this regard, the divider panels are sized to near outer flap box depth, which cannot be done with partitions which must fit under the inner flaps.

A further important aspect of the invention concerns the hinging of the reinforcing panels so as to prevent failure thereof during installation and during use of the box. In this regard, the corner hinge connections of the reinforcing panels comprise boxboard crushed along the hinge length, and preferably at the side thereof facing the box interior, the hinge connections also being preferably slit along portions thereof extending vertically from upper and lower edges of the hinge connections as will be described.

Finally, the invention concerns novel methods of reinforcing and internally dividing a box of the character described, important steps of the method including Z-folding a series of hinge connected reinforcing panels having an unfolded stretched out length greater than the totally collapsed length of the box so that the folded series is freely receivable within the box in a condition of parallelogram collapse. The Z-folded series of reinforcing panels is then positioned in the box and certain of the reinforcing panels are then attached to side panels of the collapsed box so that upon expansion thereof other reinforcing panel means or dividers will extend crosswise of the box interior dividing the latter into sections or compartments for receiving containers. As previously mentioned, the

assists Patented Aug. 17, 1965 hinge connections of the reinforcing panels are subjected to slitting and crushing for rengthening purposes.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following detailed description of the drawings, in which:

FIG. 1 is an elevation showing different methods of stacking boxes;

FIG. 2 shows in perspective partially broken away the interior details of a box constructed in accordance with the principles of the invention;

FIG. 3 shows an alternate form of box construction;

PEG. 4 is a plan view showing one side or face of the stretched out series of reinforcing panels;

FIG. 5 shows the opposite side of the FIG. 4 panel series;

FIG. 6 is an edge view showing the stretched out series of reinforcing panel sections;

FIG. 7 shows the FIG. 6 series after Z-folding;

FIG. 8 shows the positioning of the Z-folded panel series in a partially parallelogram collapsed box; and

FIG. 9 shows a method of pressure bonding the Z- folded reinforcing panel series to the side panels of the box.

Referring first to FIG. 1, boxes are shown stacked in columns 143 and 11 the latter illustrating crosswise stacking tending to exert an extreme load on the center sections of each box as designated at 12. As previously mentioned, it is one purpose of the invention to provide reinforcing and internal support opposing the tendency of the box center section to cave particularly under the conditions of stacking illustrated by the column ill, the caving problem being acute when thin walled plastic containers are shipped in boxboard boxes.

FIG. 2 shows a high strength collapsible box incorporating the invention, the box itself comprising boxboard side panels 13 and end panels 14 with corner hinging at 15 so that the box has positions of progressive parallelogram collapse as seen in FIGS. 8 and 9. The box also includes closure flap means typically including upper and lower pairs of end closure flaps 16 hinged to the upper terminals of the box end panels at 1'7, and upper and lower pairs of side closure flaps 18 hinged to the upper terminals of the box side flaps at 19.

As viewed in FIG. 2 a serpentine series 29 of boxboard reinforcing panels 21-27 extends within the box interior with corner hinging and with attachment to the box side panels 13 so that series alternate reinforcing panels 22, 24 and 26 extend crosswise of the box interior and remain parallel to the box end panels 14 in different positions of progressive parelle-logram collapse of the box. The hinge connections of the reinforcing panels are illustrated at 28, 29, 3t), 31, 32 and 33 and it will be understood that the axes of these connections remain generally parallel to the axes of the hinge connections 15 be tween the box side and end flaps.

The reinforcing panels 21, 23, 2'5 and 27 are attached as by bonding to the inner faces of the box opposite sides 13, typically as shown in FIG. 2, the bond area between the reinforcing panels 21 and 25, and the box side panel 13 being designated generally at 34 and. 35. Typically, the bond may comprise a suitable adhesive cement or glue, and it will be noted that the glue zone is restricted or spaced from the upper and lower edges of the reinforcing panels. Accordingly, when the box side and end panels are cut at locations above the line 36 corresponding to the upper limit of the glue zone, the box extent above the sever may be freely lifted since it is not attached to the reinforcing panels. Such severing is oftentimes desired when removing containers from the box or when displays of boxes withcontainers are to be formed.

FIG. 2 shows the series alternate reinforcing panels 22, 2.4 and 26 to have upper edges 37, 33 and 39 positioned to transmit closed flap loading otherwise tending to crush the center regions of the box. In this regard, the closure flaps 16 will be understood as being extensible in horizontally spaced relation in closed position as indicated by the broken line 44), in which position the series alternate reinforcing panels 22, 24 and 26 project upwardly between the closed horizontal positions of the end closure flaps 16. At the same time, the side closure flaps 18 are closable to horizontal position overlying the end flaps 116, the undersides of the flaps 18 having downward facing contact with the upper edges 37, 38 and 39 of the divider panels. Accordingly, loading transmitted downwardly to the outer panels 18 in closed position is transferrable directly to the divider panels and then to the box side walls 13 and to the box lower closure panels 18 for transfer to the next lower box. As previous ly explained, this construction affords materially increased strength and internal support to the box, as demonstrated by crush loading tests with and without the divider.

Referring now to FIGS. 4-6, the series of reinforcing panels is shown in stretched out condition prior to positioning of the divider within the box interior. The divider or series of reinforcing panels is typically con structed of boxboard as better seen in FIG. 6 wherein a corrugated sheet 40 is sandwiched between outer sheets 41 and 42 and glued in position to form an integrated assembly. It is an important feature of the invention that the reinforcing panel means is locally crushed at the hinge locations thereby to form the series of hinge connected panels 2l27. Furthermore, the crushing is carried out to form crush recesses opening toward the interior of the box as best seen in FIG. 2. Accordingly, that side of the panel means shown in FIG. 4 is crushed at the hinge locations 29, 30 and 33, whereas that side of the panel means shown in FIG. 5 is crushed at the locations 28, 31 and 32. It is also an important feature of the "invention that the panel means is slit along portions of the hinge lengths extending vertically from the upper and lower edges of the hinge connections. Accordingly, the sheet 42 in FIG. 4 is slit at the hinge locations 29, 31 and 33, whereas the sheet 41 in FIG. 5 is slit at the hinge locations 28, 30 and 32. In this regard, the crushed zones are designated by the shading 43, whereas the slits are designated by the lines 44 in FIGS. 4 and 5. The crushed recesses and the slits are also physically shown by the same number-s in FIGS. 6 and 7. It is found that the crushing and slitting of the reinforcing panel at the hinge locations and in the manner described affords r maximum strength and prevents rupture of the hinges during formation, installation and use of the panel means.

FIG. 2 also illustrates the cutting away of the closure flaps 16 at the locations so as not to interfere with the reinforcing panels 21 and 27 when the closure flaps are swung to closed position. Also, FIG. 2 shows that the reinforcing panels 21 and 27 terminate at 46 in spaced relation to the box end panels 14, this construction illustrating the fact that the reinforcing panel means is freely insertable within the box interior while the box is partially collapsed, as shown in FIG. 8.

Prior to insertion of the reinforcing panel means within the box interior, the panel means 20 is given a Z or S fold as illustrated in FIG. 7 so that the center divider panel 24 lies sandwiched between the panels 22 and 23 on one side and the panels 25 and 26 on the other side. The Z-folding step is carried out after the panel structure has been crushed and slit as previously described. In addition, and adhesive or bonding agent may be applied to the panels 21, 23, 2,5 and 27 at the locations 34, 35, 46 and 47 as illustrated in FIG. 7, either before, during or after Z-folding. Thereafter, the folded series of panels 21-27, is inserted into the box which is in partially parallelogram collapsed condition as shown in FIG. 8, and in such a way that the axes of the reinforcing panel hinges extend generally parallel to the box side and end panels hinge connection axes. The box is then closed fiat while the inserted divider 20 is held in indexed position, i.e. the position in which the bonding agent is to be bonded to the inner faces of the box side panels 13. Pressure is then applied to the flattened box until the adhesive hardens. This step is typically carried out by locating the assembly between a pair of pressure belt conveyors 48 and 49 shown in FIG. 9, which may carry the flattened assembly between additional pressure exerting members such as rollers 5% or other suitable members.

After hardening of the adhesive the collapsed box may then be parallelogram expanded to the condition shown in FIG. 2 and it will be found that the divider panels 22, 2 and 26 have been extended crosswise 0f the box interior, remaining parallel to the box and panel 14 throughout expansion of the box.

FIG. 3 shows a slightly modified form of the invention wherein the divider panel means 51 is dimensioned so as to cooperate with the box side and end panels 52 and 53 respectively to form equal sized compartments 54-57 for receiving pairs of half gallon plastic containers. The spacing between the crosswise extending divider panels 58 and 59 and the box end panels 53 is again greater than the width dimensions of the end flap closures 6t), so that the divider panels may directly support the box side closure flaps 61 in closed position. In the construction shown in FIG. 2, the box and divider panel series are sized to contain six quart sized plastic containers in each of the compartment-s formed between the box end panels 15 and the divider panels 22 and 26. The compartments formed between the divider panels 22, 24 and 26 are each sized to receive three quart containers.

We claim:

1. A high strength collapsible box, comprising boxboard side panels and end panels with corner hinging so that the box has positions of progressive parallelogram collapse, and a serpentine series of boxboard reinforcing panels extending within the box interior with corner hinging and with attachement to said box side panels so that series alternate reinforcing panels extend crosswise of the box interior and remain parallel to said box end panels in said positions of progressive parallelogram collapse said corner hinging being locally crushed to reduce the hinging thickness and having slits extending part way along the crushed hinge lengths.

2. The invention as defined in claim 1 in which the box includes closure flap means, and said series alternate reinforcing panels have edges positioned to transmit closed flap loading tending to crush the box.

3. The invention as defined in claim 2 in which the closure flap means includes a pair of end closure flaps hinged to the upper terminal of said box end panels so as to extend in horizontally spaced relation in closed position, said series alternate reinforcing panels projecting upwardly between said closed positions of the end closure flaps.

4. The invention as defined in claim 3 in which the closure flap means includes side closure flaps hinged to the upper terminals of said box side flaps so as to extend horizontally in closed position with the undersides of the side closure flaps in downward facing contact with upper edges of said series alternate reinforcing panels.

5. A high strength collapsible box, comprising boxboard side panels and end panels with corner hinging so that the box has positions of progressive parallelogram collapse, and a serpentine series of internally corrugated boxboard reinforcing panels extending vertically within the box interior, certain of said reinforcing panels being bonded to said side panels and other of said reinforcing panels having corner hinge connections to said certain panels so as to extend crosswise of the box interior while remaining parallel to said box end panels in said positions of progressive parallelogram collapse, said corner hinge connections comprising boxboard locally crushed along the hinge lengths and at the sides thereof facing the box interior to locally reduce the connection thicknesses, and slit along portions of the crushed hinge lengths extending inwardly of the hinge connections from upper and lower edges thereof, said corner hinge connections being adjacent said side panels. 4

6. The invention as defined in claim 5 in which the bonding of said certain reinforcing panels to the box side panels is restricted to bonding zones spaced from the upper and lower edges of the reinforcing panels.

7. The invention as defined in claim5 in which the end reinforcing panels of said serpentine series are bonded to the box side panels and are spaced from the box end panels.

8. An assembly of the character described, comprising a box having hinge connected side and end panels in a condition of parallelogram collapse, and a series of hinge connected reinforcing panels received within the box interior so that the box and reinforcing panel hinge axes extend generally parallel, said reinforcing panel series having an unfolded stretched out length greater than the totally collapsed length of the box, and said reinforcing panel series being Z-folded in the box for attachment of certain reinforcing panels to the box side panels in collapsed state, whereby opening of the box will swing other reinforcing panel means to extend crosswise of the box interior dividing said interior into container receiving sections said corner hinging being locally crushed to reduce the hinging thickness and having slits extending part Way References Cited by the Examiner UNITED STATES PATENTS 543,991 8/95 Johnson 22915 2,188,732 1/40 Vogt 229-27 2,580,180 12/51 Meller 9349 2,866,585 12/58 Alexander 229-15 2,900,120 8/59 Wichman 22915 3,009,625 11/61 Arkley et al. 22941 3,014,415 12/61 Pierce 93--49 FOREIGN PATENTS 641,721 5/62 Canada.

562,778 7/44 Great Britain.

THERON E. CONDON, Primary Examiner. EARLE I. DRUMMOND, Examiner. 

1. A HIGH STRENGTH COLLAPSIBLE BOX, COMPRISING BOXBOARD SIDE PANELS AND END PANELS WITH CORNER HINGING SO THAT BOX HAS POSITIONS OF PROGRESSIVE PARALLELOGRAM COLLAPSE, AND A SERPENTINE SERIES OF BOXBOARD REINFORCING PANELS EXTENDING WITHIN THE BOX INTERIOR WITH CORNER HINGING AND WITH ATTACHMENT TO SAID BOX SIDE PANELS SO THAT SERIES ALTERNATE REINFORCING PANELS EXTEND CROSSWISE OF THE BOX INTERIOR AND REMAIN PARALLEL MTO SAID BOX END PANELS IN SAID POSITIONS OF PROGRESSIVE PARALLELOGRAM COLLAPSE SAID CORNER HINGING BEING LOCALLY CRUSHED TO REDUCE THE HINGING THICKNESS AND HAVING SLITS EXTENDING PART WAY ALONG THE CRUSHED HINGE LENGTHS. 